Percutaneously absorbable compositions of morphine or analogous analgesics of morphine

ABSTRACT

A composition which is percutaneously absorbable, including a narcotic analgesic selected from the group consisting of morphine and analogous analgesics thereof; from 1 to 20 weight percent of a percutaneous absorption accelerator comprised of one of (a) a terpene and (b) an essential oil; from 10 to 60 weight percent of a percutaneous absorption accelerating assistant comprised of one of (a) a lower alcohol having 1-5 carbon atoms, (b) water and (c) a lower glycol having 2-5 carbon atoms.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to percutaneously absorbable formulations such as analgesics such as morphine, or its salts or bases.

2. Background of the Related Art

Narcotic analgesics such as morphine or its salts and nonnarcotic analgesics such as eptazocine have been orally administered or injected to ease postoperative and cancerous pains.

In the case of such injecting agents, at-home treatment is difficult because of the necessity of administration by a third person, and further medicines having short working times such as morphine are disadvantageously difficult to administer at the time of acute pain because of its increased administration frequency.

Oral agents, which have been developed for the purpose of simplification of administration and use, overcame some disadvantages of the injecting agents, but are not so much improved in working time, in which the migrating property and retentivity of the formulations in digestive organs are difficult to control even by pharmaceutical designs for gradual release, and the persistency has its limit.

Further, many cancer patients in the last stage can not have oral administration of analgesics because of vomiting and nausea which are the side effects of carcinostatic substances.

On the other hand, formulations applied to the skin have an expected persistency of medicinal effect of about 24 hours to 1 week for one administration, and are applicable to patients for which oral administration is not possible.

In general, medicines have low percutaneous absorbability, and it is the same with analgesics including morphine and its salts.

The main barrier to percutaneous absorption of medicines resides in a horny layer, and various accelerators have been developed as the accelerators were considered to increase the percutaneous absorbability to the lipids of the horny layer. However, the medicine permeability of the epidermis other than the horny layer becomes the barrier in simple absorption accelerators acting on the horny layer and combinations thereof, so that very excellent accelerators have not been developed yet.

In view of the disadvantages of the prior arts, as a result of the earnest studies on utilization of analgesics such as morphine, which were used only as injecting agents and oral agents in the past, for percutaneously absorbable type external agents such as ointment, cream, tape dressing, plaster dressing, patch dressing, and pap dressing (wet dressing), the present inventors have found and attained this invention.

SUMMARY OF THE INVENTION

The present invention can provide a percutaneously absorbable formulation by dissolving a percutaneously absorbable composition of narcotic or nonnarcotic analgesics into a base agent formed of a percutaneous absorption accelerator consisting of a terpene and/or an essential oil and a percutaneous absorption accelerating assistant consisting of a lower alcohol having 1-5 carbon atoms.

As the narcotic analgesics used in the present invention, morphine hydrochloride, ethylmorphine hydrochloride, morphine sulfate, cocaine hydrochloride, pethidine hydrochloride, codeine phosphate, dihydrocodeine phosphate, fentanyl citrate, sufentanil, meperidine hydrochloride and the like are used. As the nonnarcotic analgesics, eptazocine hydrobromide, buprenorphine hydrochloride, butorphanol tartrate, or other salts are used. These analgesics may be constituted by basic ones.

As the percutaneous absorption accelerators, hydrocarbon monoterpenes such as limonene, monoterpene alcohols such as l-menthol, terpineol and borneol, monoterpene aldehydes such as citral, monoterpene ketones such as ionone, other monoterpenes such as cineole, or essential oils containing monoterpenes such as mentha oil, peppermint oil, and eucalyptus oil are used.

As the percutaneous absorption accelerating assistants, lower alcohols having 1-5 carbon atoms such as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, amyl alcohol, isopropyl alcohol and the like are used.

The blending quantities are varied depending on the kinds of medicines used, but the percutaneous absorption accelerator is preferably used in a ratio of 1-20 wt. % and the percutaneous absorption accelerating assistant in a ratio of 10-60 wt. %.

As other percutaneous absorption accelerators, alcohols having 8-22 carbon atoms, fatty acids having 8-22 carbon atoms, fatty acid methyl, ethyl, vinyl, n-propyl, isopropyl, propylene, n-butyl, isobutyl and buthylene esters having 8-22 carbon atoms, n-alkylpyrrolidones having 1-16 carbon atoms and/or mixtures thereof may be added.

Further, as other percutaneous absorption accelerating assistants, water, lower glycols having 2-20, preferably 2-5, carbon atoms such as glycerol and propylene glycol, lower ketones having 2-5 carbon atoms, or aldehyde may be added.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-11 are graphs showing the changes on standing of absorption quantities of medicines through the skin with various kinds and quantities of medicines, percutaneous absorption accelerators, and percutaneous absorption accelerating assistants related to the formulations according to the examples of the present invention and the formulations of comparative examples.

EFFECT

The percutaneous absorption accelerator in the composition physically removes the barrier ability of the horny layer of the skin and enhances the medicine permeability of the skin.

The percutaneous absorption accelerating assistant increases the solubility of the medicine and also medicine permeability, resulting in a remarkable improvement in absorbability of the medicine as a synergistic effect.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is further illustrated in detail according to following examples.

EXAMPLE 1

Formulations as shown in Table 1 were prepared, and comparatively examined for the change on standing of skin permeating quantity by means of a skin permeation test method described below.

Skin Permeation Test Method

The abdominal extracted skin of a hairless rat (male, body weight 150 g, available from Saitama Experimental Animals) was put in a 2-chamber diffusing cell (contact area: 1.0 cm²) of a skin permeation test and held at 37° C. Then, 2.5 ml of a medicine solution was put on the horny layer side, and 2.5 ml of water on the derm side. Ten diffusing cell dermic solutions were sampled and the lapse of time, and the quantities of the medicine permeated through the skin after 2, 4, 6, 8 and 10 hours were measured. The results are as shown in Table 2 and FIG. 1.

                  TABLE 1                                                          ______________________________________                                         unit: w %                                                                      Sample        This Invention                                                                             Comparative Example                                  Component     1           1        2    3                                      ______________________________________                                         Morphine hydrochloride                                                                        1           1       1     1                                     1-Menthol      5          --      --    5                                      Ethanol       40          --      40    --                                     Water         54          99      59    4                                      ______________________________________                                    

                                      TABLE 2                                      __________________________________________________________________________     unit: μg/cm.sup.2                                                               This Invention                                                                           Comparative Ex.                                                                          Comparative Ex.                                                                          Comparative Ex.                              Time                                                                               1         1         2         3                                            elapsed                                                                            Mean                                                                               Deviation                                                                            Mean                                                                               Deviation                                                                            Mean                                                                               Deviation                                                                            Mean                                                                               Deviation                                __________________________________________________________________________     2    629                                                                               20.9  1.72                                                                               0.25  3.58                                                                               0.52  10.2                                                                               3.73                                     4   1436                                                                               87.3  3.43                                                                               0.01  10.3                                                                               1.54  49.3                                                                               0.12                                     6   1732                                                                               90.9  6.34                                                                               0.23  23.0                                                                               5.59  161 10.1                                     8   1893                                                                               111   12.6                                                                               1.78  40.6                                                                               11.4  321 20.1                                     10  --  --    17.1                                                                               3.19  73.3                                                                               15.1  533 20.0                                     __________________________________________________________________________

The results showed that the formation having l-menthol selected as an absorption accelerator and ethanol as an absorption accelerating assistant has excellent percutaneous absorptivity.

EXAMPLE 2

To examine the relation of the concentration of morphine hydrochloride with skin permeativity, formations shown in Table 3 were prepared and examined on the basis of the skin permeation test.

                  TABLE 3                                                          ______________________________________                                         unit: w %                                                                                     This lnvention                                                  Component        1          2     3                                            ______________________________________                                         Morphine hydrochloride                                                                          1          10    0.01                                         1-Menthol        5           5    5                                            Ethanol          40         40    40                                           Water            54         45    54.99                                        ______________________________________                                    

As shown in FIGS. 2(a), 2(b) nd 2(c), and Table 4, the results showed that the medicine is absorbed percutaneously corresponding to the concentration of morphine hydrochloride, i.e., 0.01 W % in FIG. 2(a), 1 W % in FIG. 2(b), and 10 W % in FIG. 2(c).

                                      TABLE 4                                      __________________________________________________________________________     unit: μg/cm.sup.2                                                               This Invention                                                                             This Invention                                                                           This Invention                                       Time                                                                               1           2         3                                                    elapsed                                                                            Mean Deviation                                                                             Mean                                                                               Deviation                                                                            Mean Deviation                                       __________________________________________________________________________     2    629 20.9    6256                                                                              213   8.45 0.08                                            4   1436 87.3   14399                                                                              671   17.4 0.34                                            6   1732 90.9   20323                                                                              940   27.7 1.03                                            8   1893 111    24958                                                                              1142  35.0 0.63                                            10  --   --     18410                                                                              1580  40.4 0.88                                            __________________________________________________________________________

EXAMPLE 3

Formulations containing different kinds of percutaneous absorption accelerators were prepared as shown in Table 5, and comparatively examined for percutaneous absorbability of morphine hydrochloride in the same manner as in Example 1.

                  TABLE 5                                                          ______________________________________                                         unit: w %                                                                                    This Invention                                                   Component       1          4      5                                            ______________________________________                                         Morphine hydrochloride                                                                         1          1      1                                            1-Menthol       5          --     --                                           Terpineol       --         5      --                                           Peppermint oil  --         --     5                                            Ethanol         40         40     40                                           Water           54         54     54                                           ______________________________________                                    

Consequently, as shown in FIG. 3 and Table 6, excellent percutaneous absorbability was shown for every percutaneous absorption accelerator, but particularly the best was terpineol.

                                      TABLE 6                                      __________________________________________________________________________     unit: μg/cm.sup.2                                                               This Invention                                                                             This Invention                                                                           This Invention                                       Time                                                                               1           4         5                                                    elapsed                                                                            Mean Deviation                                                                             Mean                                                                               Deviation                                                                            Mean Deviation                                       __________________________________________________________________________     2    629 20.9   1046                                                                               44.5   854 65.2                                            4   1436 87.3   2111                                                                               107   1766 64.7                                            6   1732 90.9   3163                                                                               226   2283 73.3                                            8   1893 111    3884                                                                               223   2662 93.8                                            10  --   --     --  --    3087 100                                             __________________________________________________________________________

EXAMPLE 4

To examine the effect of the concentration of l-menthol on the skin permeability of morphine hydrochloride from an l-menthol-ethanol-water system, formations as shown in Table 7 were prepared and examined for percutaneous absorbability.

                  TABLE 7                                                          ______________________________________                                         unit: w %                                                                      Sample        This Invention                                                                               Comparative Ex.                                    Component     6       1     7     4      5                                     ______________________________________                                         Morphine hydrochloride                                                                       1       1      1    1      1                                     1-Menthol     2.5     5     10    1      0.1                                   Ethanol       40      40    40    40     40                                    Water         56.4    54    49    58     58.9                                  ______________________________________                                    

As shown in FIG. 4 and Table 8, the results showed that skin permeativity is excellent when the concentration of menthol is 2.5 w % or more.

                                      TABLE 8                                      __________________________________________________________________________     unit: μg/cm.sup.2                                                               This Invention                                                                           This Invention                                                                           This Invention                                                                           Comp. Ex. Comp. Ex.                          Time                                                                               1         6         7         4         5                                  elapsed                                                                            Mean                                                                               Deviation                                                                            Mean                                                                               Deviation                                                                            Mean                                                                               Deviation                                                                            Mean                                                                               Deviation                                                                            Mean                                                                               Deviation                      __________________________________________________________________________     2    629                                                                               20.9   292                                                                               39.8   524                                                                               67.1  0.0 0.0   0.0 0.0                            4   1436                                                                               87.3   876                                                                               47.4  1164                                                                               88.0  18.34                                                                              2.77  2.42                                                                               0.63                           6   1732                                                                               90.9  1340                                                                               62.4  1665                                                                               94.8  83.4                                                                               15.5  6.90                                                                               1.27                           8   1893                                                                               111   1717                                                                               57.8  2020                                                                               65.0  226 40.3  19.0                                                                               2.02                           10  --  --    2057                                                                               71.9  2271                                                                               58.3  450 63.4  30.4                                                                               2.28                           __________________________________________________________________________

EXAMPLE 5

To examine the effect of the concentration of ethanol, which is a percutaneous absorption accelerating assistant, on skin permeativity of morphine hydrochloride from an l-menthol-ethanol-water system, the formulations shown in Table 9 were prepared and examined for percutaneous absorbability.

                  TABLE 9                                                          ______________________________________                                         unit: w %                                                                      Sample         This Invention                                                                              Comparative Ex.                                    Component      8      1      9    6      7                                     ______________________________________                                         Morphine hydrochloride                                                                        1      1      1    1      1                                     1-Menthol      5      5      5    5      5                                     Ethanol        20     40     60   80     94                                    Water          74     54     34   14     --                                    ______________________________________                                    

As shown in FIG. 5 and Table 10, the results showed that skin permeativity is excellent when the concentration of ethanol is 20 w % or more and less than 60 w %.

                                      TABLE 10                                     __________________________________________________________________________     unit: μg/cm.sup.2                                                               This Invention                                                                           This Invention                                                                           This Invention                                                                            Comp. Ex. Comp. Ex.                         Time                                                                               1         8         9          6         7                                 elapsed                                                                            Mean                                                                               Deviation                                                                            Mean                                                                               Deviation                                                                            Mean Deviation                                                                            Mean                                                                               Deviation                                                                            Mean                                                                               Deviation                     __________________________________________________________________________     2    629                                                                               20.9  45.0                                                                               4.08  15.9 2.0   0.72                                                                               0.7   0.76                                                                               0.76                          4   1436                                                                               87.3  182 0.80  251  6.84  6.84                                                                               1.02  5.92                                                                               4.72                          6   1732                                                                               90.9  366 18.3  688  33.6  33.6                                                                               0.13  25.8                                                                               18.6                          8   1893                                                                               111   570 62.1  1106 226   104 0.29  66.6                                                                               46.3                          10  --  --    942 87.4  --   --    --  --    --  --                            __________________________________________________________________________

EXAMPLE 6

To examine the effect of the concentration of isopropyl alcohol (IPA), employed instead of ethanol, on skin permeativity of morphine hydrochloride from an l-menthol-alcohol-water system, the formulations shown in Table 11 were prepared and examined for percutaneous absorbability.

                  TABLE 11                                                         ______________________________________                                         unit: w %                                                                                     This lnvention                                                  Component        10         11    12                                           ______________________________________                                         Morphine hydrochloride                                                                           1          1     1                                           1-Menthol         5          5     5                                           Ethanol          20         40    60                                           Water            74         54    34                                           ______________________________________                                    

Consequently, as shown in FIG. 6 and Table 12, the skin permeativity was excellent when the concentration of isopropyl alcohol is 20 wt. % or more and less than 60 wt. % similar to the case of ethanol, and too high a concentration aggravated the absorbability.

                                      TABLE 12                                     __________________________________________________________________________     unit: μg/cm.sup.2                                                               This Invention                                                                           This Invention                                                                           This Invention                                                                           This Invention                               Time                                                                               1         10        11        12                                           elapsed                                                                            Mean                                                                               Deviation                                                                            Mean                                                                               Deviation                                                                            Mean                                                                               Deviation                                                                            Mean                                                                               Deviation                                __________________________________________________________________________     2    629                                                                               20.9   229                                                                               44.4   348                                                                               31.8  3.43                                                                               2.80                                     4   1436                                                                               87.3   665                                                                               94.7  1663                                                                               75.3  75.8                                                                               13.0                                     6   1732                                                                               90.9  1073                                                                               145   2624                                                                               68.2  227 32.6                                     8   1893                                                                               111   1546                                                                               184   3420                                                                               64.1  432 48.5                                     10  --  --    1922                                                                               178   3891                                                                               40.4  696 65.6                                     __________________________________________________________________________

EXAMPLE 7

Instead of water added as the supplement to ethanol for the percutaneous absorption accelerating assistant having an influence on skin permeativity of morphine hydrochloride from an l-menthol-alcohol-water system, glycerol was mixed as shown in Table 13, and this was comparatively examined for percutaneous absorbability.

As shown in FIG. 7 and Table 14, the results showed that a percutaneous absorbability similar to that for water can be held when glycerol is used.

                  TABLE 13                                                         ______________________________________                                         unit: w %                                                                      Sample             This Invention                                              Component          1       13                                                  ______________________________________                                         Morphine hydrochloride                                                                             1       1                                                  1-Menthol           5       5                                                  Ethanol            40      40                                                  Water              54      --                                                  Glycerol           --      54                                                  ______________________________________                                    

                  TABLE 14                                                         ______________________________________                                         unit: μg/cm.sup.2                                                                   This Invention  This Invention                                         Time    1               13                                                     elapsed Mean    Deviation   Mean   Deviation                                   ______________________________________                                         2        629    20.9        26.8   8.40                                        4       1436    87.3        235    76.8                                        6       1732    90.9        687    163                                         8       1893    111         1172   169                                         10      --      --          1568   144                                         ______________________________________                                    

EXAMPLE 8

To examine the skin permeativities of other medicines to an l-menthol-ethanol-water system, formulations using fentanyl citrate (FTC), eptazocine hydrobromide (ETH), cocaine hydrochloride (CCH), and morphine hydrochloride were prepared and examined for percutaneous absorbability.

                  TABLE 15                                                         ______________________________________                                         unit: w %                                                                      Sample            This Invention                                               Component         1     14        15  16                                       ______________________________________                                         Morphine hydrochloride                                                                           1     --        --  --                                       FTC               --     1        --  --                                       ETH               --    --         1  --                                       CCH               --    --        --   1                                       1-Menthol         5      5         5   5                                       Ethanol           40    40        40  40                                       Water             54    54        54  54                                       ______________________________________                                    

As shown in FIG. 8(a), FIG. 8(b) and FIG. 8(c) and Table 16, the results showed that every formulation is excellent in skin permeativity in the 1-menthol-ethanol-water system, i.e.,

FTC, sample 14, FIG. 8(a);

ETH, sample 15, FIG. 8(b), and

CCH, sample 16, FIG. 8(c).

                                      TABLE 16                                     __________________________________________________________________________     unit: μg/cm.sup.2                                                               This Invention                                                                           This Invention                                                                           This Invention                                                                           This Invention                               Time                                                                               1         14        15        16                                           elapsed                                                                            Mean                                                                               Deviation                                                                            Mean                                                                               Deviation                                                                            Mean                                                                               Deviation                                                                            Mean                                                                               Deviation                                __________________________________________________________________________     2    629                                                                               20.9   570                                                                               19.5   586                                                                               61.7   495                                                                               11.2                                     4   1436                                                                               87.3  1539                                                                               56.4  1729                                                                               87.8  1353                                                                               13.7                                     6   1732                                                                               90.9  2274                                                                               66.9  2349                                                                               57.9  2018                                                                               40.4                                     8   1893                                                                               111   3086                                                                               122   3095                                                                               52.0  2549                                                                               14.3                                     10  --  --    3692                                                                               187   3691                                                                               50.7  2694                                                                               38.1                                     __________________________________________________________________________

EXAMPLE 9

To examine the effect of different concentration of l-menthol on skin permeativity of eptazocine hydrobromide from an l-menthol-ethanol-water system, formulations as shown in Table 17 were prepared and examined for percutaneous absorbability.

                  TABLE 17                                                         ______________________________________                                         unit: w %                                                                      Sample      This Invention                                                     Component   17            18     15                                            ______________________________________                                         E.T.H.       1             1      1                                            l-Menthol    1             2      5                                            Ethanol     40            40     40                                            Water       58            57     54                                            ______________________________________                                    

As shown in FIG. 9 and Table 18, the results showed that skin permeativity is excellent when the concentration of menthol is 1.0 wt. % or more.

                                      TABLE 18                                     __________________________________________________________________________     unit: μg/cm.sup.2                                                               This Invention                                                                             This Invention                                                                           This Invention                                       Time                                                                               17          18        15                                                   elapsed                                                                            Mean Deviation                                                                             Mean                                                                               Deviation                                                                            Mean Deviation                                       __________________________________________________________________________     2   55.03                                                                               67.10  669.7                                                                              170.8 586.3                                                                               61.70                                           4   556.3                                                                               380.3  1638                                                                               117.0 1729 87.77                                           6   1264 275.4  2063                                                                               99.52 2349 57.93                                           8   1922 223.9  2623                                                                               36.51 3095 52.03                                           10  2407 170.8  3017                                                                               44.86 3691 50.61                                           __________________________________________________________________________

EXAMPLE 10

To examine the effect of the concentration of ethanol on skin permeativity of eptazocine hydrobromide from an l-menthol-ethanol-water system, formulations as shown in Table 19 were prepared and examined for percutaneous absorbability.

                  TABLE 19                                                         ______________________________________                                         unit: w %                                                                      Sample      This Invention                                                     Component   19            20     15                                            ______________________________________                                         E.T.H.       1             1      1                                            l-Menthol    5             5      5                                            Ethanol     10            20     40                                            Water       84            73     54                                            ______________________________________                                    

As shown in FIG. 10 and Table 19, the results showed that skin permeativity is excellent when the concentration of ethanol is 10 wt. % or more.

                                      TABLE 20                                     __________________________________________________________________________     unit: μg/cm.sup.2                                                               This Invention                                                                            This Invention                                                                            This Invention                                       Time                                                                               19         20         15                                                   elapsed                                                                            Mean Deviation                                                                            Mean Deviation                                                                            Mean Deviation                                       __________________________________________________________________________     2   9.121                                                                               9.592 97.25                                                                               14.79 586.3                                                                               61.70                                           4   127.3                                                                               78.04 324.6                                                                               187.0 1729 87.77                                           6   393.5                                                                               207.5 1138 195.9 2349 57.93                                           8   755.6                                                                               303.4 1599 243.3 3095 52.03                                           10  1170 276.0 2152 422.4 3691 50.61                                           __________________________________________________________________________

EXAMPLE 11

To examine the effect of concentration of eptazocine hydrobromide on skin permeativity of eptazocine hydrobromide from an l-menthol-ethanol-water system, formulations as shown in Table 21 were prepared and examined for percutaneous absorbability.

                  TABLE 21                                                         ______________________________________                                         unit: w %                                                                      Sample      This Invention                                                     Component   21            22     15                                            ______________________________________                                         E.T.H.      0.1            5      1                                            l-Menthol   5              5      5                                            Ethanol     40            40     40                                            Water       54.9          50     54                                            ______________________________________                                    

As shown in FIG. 11 and Table 22, the results showed that skin permeativity is excellent when the concentration of eptazocine bromohydride is 1.0 wt. % or more.

                                      TABLE 22                                     __________________________________________________________________________     unit: μg/cm.sup.2                                                               This Invention                                                                             This Invention                                                                           This Invention                                       Time                                                                               19          20        15                                                   elapsed                                                                            Mean Deviation                                                                             Mean                                                                               Deviation                                                                            Mean Deviation                                       __________________________________________________________________________     2   53.82                                                                               2.934   1418                                                                              586.3   586.3                                                                             61.70                                           4   132.2                                                                               13.47   8013                                                                              328.3 1729 87.77                                           6   206.1                                                                               26.52  14273                                                                              549.4 2349 57.93                                           8   268.2                                                                               23.03  19415                                                                              103.5 3095 52.03                                           10  311.0                                                                               27.65  23300                                                                              913.5 3691 50.61                                           __________________________________________________________________________

INDUSTRIAL APPLICABILITY

The percutaneous absorption accelerating formations according to the present invention allow the administration from the skin for medicines which could not be administered from the skin in the past by adapting monoterpenes which were only used as perfumes as percutaneous absorption accelerators and lower alcohols having 1-5 carbon atoms as skin absorption accelerating assistants, and combining them.

As the prevent invention is constituted for percutaneous absorption, formulations having long analgesic effects can be provided.

The formulations according to the present invention are suitable for at-home treatment because of their easy recipe, compared with injecting agents and oral agents, and excellent in persistency. 

What is claimed is:
 1. A composition which is percutaneously absorbable, comprising:a narcotic analgesic selected from the group consisting of morphine and analogous analgesics thereof; from 1 to 20 weight percent of a percutaneous absorption accelerator comprised of one of (a) a terpene and (b) an essential oil; from 10 to 60 weight percent of a percutaneous absorption accelerating assistant comprised of one of (a) a lower alcohol having 1-5 carbon atoms, (b) water and (c) a lower glycol having 2-5 carbon atoms.
 2. The composition according to claim 1, wherein the percutaneous absorption accelerator is one of (a) a monoterpene and (b) an essential oil containing a monoterpene.
 3. The composition according to claim 2, wherein the percutaneous absorption accelerator is a monoterpene and is one of (a) 1-menthol and (b) terpineol.
 4. The composition according to claim 3, wherein the percutaneous absorption accelerating assistant is at least one lower alcohol having 1-5 carbon atoms selected from the group consisting essentially of methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, or amyl alcohol.
 5. The composition according to claim 2, wherein the percutaneous absorption accelerator is an essential oil containing a monoterpene and is one of (a) mentha oil and (b) peppermint oil.
 6. The composition according to claim 5, wherein the percutaneous absorption accelerating assistant is at least one lower alcohol having 1-5 carbon atoms selected from the group consisting essentially of methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, and amyl alcohol.
 7. The composition according to claim 2, wherein the percutaneous absorption accelerating assistant is at least one lower alcohol having 1-5 carbon atoms selected from the group consisting essentially of methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, and amyl alcohol.
 8. The composition according to claim 1, wherein the percutaneous absorption accelerating assistant is at least one lower alcohol having 1-5 carbon atoms selected from the group consisting essentially of methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, or amyl alcohol.
 9. The composition according to claim 1, wherein the analogous analgesics of morphine include salts of morphine and bases of morphine.
 10. The composition according to claim 9, wherein the analogous analgesics of morphine are selected from the group consisting essentially or morphine hydrochloride, ethyl morphine hydrochloride, and morphine sulfate. 